Deformable medical implant

ABSTRACT

The present invention comprises an implantable subcutaneous port for anchoring a transcutaneous treatment component. The implantable subcutaneous port comprises a body portion and one or more frangible lines formed within the body portion. The body portion is adapted for receiving the transcutaneous treatment component beneath the point of entry into the physiology of a patient and routing the transcutaneous treatment component. The body portion is produced from a deformable material and has an area footprint and defines a support wall through which the transcutaneous treatment component enters the body portion. Fracturing the one or more frangible lines formed within the body portion enables removal of the body portion from the physiology of a patient through a transcutaneous opening defining an area of less than thirty percent of the area footprint of the body portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of medical devices.In particular, the present invention relates to long term, implantabledevices that permits access to inner physiology and that enablenon-traumatic removal following treatment.

2. Summary of the Related Art

Medically treating a patient often requires long term placement of amedical device across one or more organ systems to establish access to aspecifically targeted interior body site for diagnostic or therapeuticpurposes. One common example is the establishment of percutaneousvascular access for purposes of administering liquid therapeutic agents,removing bodily fluids for testing or monitoring, treating bodily fluidsbefore being returned to the body, and/or disposing of bodily fluids.

Particularly in the case of administering fluids to the body or removingfluids from the body continuously or periodically over an extended timeperiod, those skilled in the medical arts typically use what are knownas “permanent” catheterization techniques. These techniques employimplanted devices such as tunneled central venous catheters (CVCs) thatremain implanted for durations ranging from a few weeks to years.Examples of such implanted and related medical devices exist in thefollowing references, which are incorporated herein by reference: U.S.Pat. No. 4,266,999 (Baier); U.S. Pat. No. 4,405,305 (Stephen et al.);U.S. Pat. No. 4,488,877 (Klein et al.); U.S. Pat. No. 4,668,222(Poirier); U.S. Pat. No. 4,897,081 (Poirier et al.); U.S. Pat. No.4,935,004 (Cruz); U.S. Pat. No. 5,098,397 (Svensson et al.); U.S. Pat.No. 5,100,392 (Orth et al.); U.S. Pat. No. 5,242,415 (Kantrowitz etal.); U.S. Pat. No. 5,662,616 (Bousquet); U.S. Pat. No. 5,823,994(Sharkey et al.); U.S. Pat. No. 5,830,184 (Basta); U.S. Pat. No.5,848,987 (Baudino et al.); U.S. Pat. No. 5,882,341 (Bousquet); U.S.Pat. No. 5,989,213 (Maginot); and U.S. Pat. No. 6,033,382 (Basta).Examples of therapeutic regimens requiring such long-term continuous orperiodic access to a specific internal body location include parenteralfeeding, chemotherapy, antibiotic administration, dialysis, and chronicanesthesiology. Central catheterization for these types of proceduresare discussed in “Vascular Access for Oncology Patients” (Gallieni etal, CA Cancer J Clin 2008 doi: 10.3322/CA.208.0015).

Generally, the type of procedure that a patient requires dictateswhether a physician will utilize an acute, short term catheterizationtechnique, or a chronic, long term catheterization technique. Forexample, establishing a state of general anesthesiology in preparationfor a surgical procedure typically involves placing a CVC in a patient'sblood vessel for a relatively short period of time, such as a fewminutes to a few hours, and then removing the catheter once the surgeryis finished and the patient is revived. When performing such ananesthesiology procedure, a physician commonly uses a short termcatheterization technique to place a drug delivery catheter in a bloodvessel of the patient.

In direct contrast to this example of short term CVC placement, aphysician performing a hemodialysis procedure in a patient sufferingfrom chronic kidney failure may place a CVC in one of the patient'sblood vessels for a relatively long period of time. Such a patienttypically requires dialysis sessions three times per week for anindefinitely extended period of time. Healthy kidney function ensuresremoval of fluid, chemicals, and wastes typically filtered from aperson's blood. Hemodialysis removes these elements by sending apatient's blood to an external artificial kidney machine via thepermanent vascular access, often established by placement of a long termcatheter within the patient. A patient who is involved in such ahemodialysis regimen may need a catheter placed in a blood vessel forweeks, months, or years in order to provide a ready means for vascularaccess into that patient's bloodstream to enable these frequent lifesaving dialysis treatments.

Long term catheterization techniques typically entail inserting acatheter into a patient using a “tunneled catheter technique.” Thisprocedure involves inserting a long term catheter into the patientthrough an incision in the skin and then routing the catheter forseveral centimeters under the skin before entering deeper regions of thebody. Despite routine use, conventional tunneled catheter designsseriously compromise the ability of a patient's skin to protect thepatient's body from infection. As discussed in “IntravascularCatheter-Related Infections: New Horizons and Recent Advances” (Raad etal., Arch Internal Medicine/Vol 162, Apr. 22, 2002, Pages 871-878.),catheter-related infections are frequent events and present apotentially fatal health problem. High morbidity rate and highprocedural cost are characteristics of typical long term tunneledcatheter usage. The primary reason that the use of conventionalcatheters leads to a high rate of infection is that microorganisms enterthe body through the skin incision. A conventional tunneled catheterdevice may include a cylindrical tissue ingrowth cuff that acts as abarrier for micro-organisms entering the body and that anchors thecatheter in the subcutaneous tunnel. Such a conventional device,however, still fails to prevent undesirably high infection rates. Thisis because standard cuff designs are designed for positioning within asubcutaneous tunnel rather than at the skin entry site, which is themost effective location at which to position a tissue ingrowth cuff forpreventing infection.

Another conventional tunneled catheter design is entirely subcutaneous.This embodiment provides an advantage over traditional transcutaneoustunneled catheter designs by eliminating the need for a continuouslymaintained breach in skin and thereby reducing risk of infection. Thesesubcutaneous catheters are connected to a port disposed beneath theskin. The port is capable of accepting a needle injection of fluid andthen providing fluid to the subcutaneous catheter. The port has acompressed rubber septum on its upper surface immediately below the skinwhich is adapted for receiving a needle therethrough and resealing underresidual compressive forces once the needle is removed. These fullysubcutaneous devices present drawbacks relative to conventionaltranscutaneous catheter systems. Particularly, large bore needles wouldirreparably damage the septum, and so usage is limited to proceduresthat require low flow rates. An example of such an implanted,subcutaneous port and catheter device is provided in U.S. Pat. No.5,562,618 (Cai, et al).

Some transcutaneous tunneled catheter devices include adjustableepidermal tissue ingrowth cuff assemblies that enable skin to heal intothe devices at their entry sites into the dermis. Such devices providereduced risk of infection, and because they require no needle puncturesfor gaining access to the catheter, these assemblies enable the higherflow rates associated with conventional transcutaneous tunneled catheterdesigns. For example, the apparatus and methods disclosed in U.S. PatentApplication No. 2004/0236314 to Mark A. Saab (Saab), incorporated hereinby reference, allow a physician to place a modular dermal tissueingrowth cuff assembly precisely within a skin incision site andsubsequently adjust the location of the distal (internal) tip of acatheter assembly associated with the tissue ingrowth cuff assembly.This device comprises a base (or port) having tissue ingrowth materialthereon for securely anchoring the port at the incision site. Aphysician using such a device, therefore, has the ability to positionthe catheter tip precisely at the desired body site without disturbing,moving, or stressing the fixed tissue ingrowth cuff. Positioning themodular tissue ingrowth cuff at the skin incision site enables the skinto heal into the device and regain its ability to protect the patientfrom infection.

The use of a port with a transcutaneous catheter and skin tissueingrowth cuff assembly has resulted in numerous improvements related topatient care and well being, but they do not anticipate or address theissue of simple and efficient removal of the port once the therapy hasbeen completed and the device is no longer needed. U.S PublicationNumber 20070043323 to Davey and U.S. patent application Ser. No.11/986,451 also to Christopher Davey address systems and methods forfacilitating removal of subcutaneous tissue ingrowth devices. (Both ofthese references are incorporated herein by reference). The teachings inthese references address the problem of tissue becoming too firmlyingrown into tissue ingrowth scaffolds, thereby requiring bluntdissection of the tissue from the device. The inventions of the Daveyreferences comprise tissue ingrowth scaffolds that are at leastpartially bioabsorbable material and/or detachable from the device sothat the scaffolds remain behind when the port is removed. These easilyremoved devices nonetheless require that a physician create a largeincision through the skin to facilitate removal of the subcutaneousimplanted device, regardless of the scaffold design or material. Theneed to make a large incision to enable removal of the subcutaneousimplant significantly prolongs the procedure, greatly increases traumato the patient, and exposes the patient to another risk of infection asa result of the added extensive breach to the skin.

A need therefore exists for a subcutaneous port that anchors atranscutaneous conduit during a treatment period and then enablesremoval through a minimally sized incision in the skin that causeslittle or no additional trauma to the patient.

SUMMARY OF THE INVENTION

The present invention comprises a medical device that is capable ofimplantation within a patient for long-term treatments, such ascatheterization procedures, and a method of using the device. Theimplanted medical port of the present invention is capable of receiving,routing, and anchoring a treatment component, such as for example afluid conduit, power cable, or fiber optic cable, that extends throughthe skin into the internal physiology of the patient. The port is shapedto maximize comfort, ease of installation, and stability afterimplantation, and thus a relatively flat or domed, and generallyoval-shaped geometry is most preferable for placement and use.

In one embodiment of the implantable subcutaneous port for anchoring atranscutaneous treatment component, the implantable subcutaneous portcomprises a body portion and one or more frangible lines formed withinthe body portion. The body portion is adapted for receiving thetranscutaneous treatment component beneath the point of entry into thephysiology of a patient and routing the transcutaneous treatmentcomponent. The body portion is produced from a deformable material andhas an area footprint and defines a support wall through which thetranscutaneous treatment component enters the body portion. Fracturingthe one or more frangible lines formed within the body portion enablesremoval of the body portion from the physiology of a patient through atranscutaneous opening defining an area of less than thirty percent ofthe area footprint of the body portion.

In another embodiment, the port of the present invention furthercomprises at least one frangible line extending along a continuous pathbetween an outer perimeter of the body portion and the support wall,and/or at least one gripping element disposed on the body portion at apoint adjacent to the least one frangible line. Gripping the bodyportion and/or the at least one gripping element from a point externalto the body of a patient and applying force outward from the major planeof the body portion results in fracturing the at least one frangibleline along the continuous path between outer perimeter of the bodyportion and the annular support wall.

The present invention further comprises a method for removing asubcutaneous port for anchoring a transcutaneous treatment component. Inone embodiment the method comprises removing the treatment componentfrom the port, wherein the port comprises a body portion and one or morefrangible lines formed within the body portion. The body portion isadapted for receiving the transcutaneous treatment component beneath thepoint of entry into the physiology of a patient and routing thetranscutaneous treatment component. The body portion is produced from adeformable material and having an area footprint and defining a supportwall through which the transcutaneous treatment component enters thebody portion. Fracturing the one or more frangible lines formed withinthe body portion enables removal of the body portion from the physiologyof a patient through a transcutaneous opening defining an area of lessthan thirty percent of the area footprint of the body portion.

Following the transcutaneous treatment component removal step, themethod comprises inserting a retrieval implement through thetranscutaneous opening, grasping the body portion with the retrievalimplement near the one or more frangible lines, applying a force outwardfrom the body portion so that the one or more frangible lines fracture,thereby sectioning the body portion into one or more pieces, and pullingthe one or more pieces of the body portion through the transcutaneousopening.

These and other features and advantages of embodiments of the presentinvention are described in greater detail below with reference to thefollowing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of an embodiment of an implantablesubcutaneous port of the present invention.

FIG. 2 depicts a perspective view of an embodiment of an implantablesubcutaneous port of the present invention in use.

FIG. 3 depicts a perspective view of an embodiment of an implantablesubcutaneous port of the present invention in use.

FIG. 4 depicts a perspective view of an embodiment of an implantablesubcutaneous port of the present invention in use.

FIG. 5A depicts a perspective cross section of an embodiment of theimplantable subcutaneous port of the present invention.

FIG. 5B depicts a perspective cross section of an embodiment of theimplantable subcutaneous port of the present invention.

FIG. 6 depicts a perspective cross section of an embodiment of theimplantable subcutaneous port of the present invention

FIG. 7A depicts a perspective bottom view of an embodiment of theimplantable subcutaneous port of the present invention during one stageof removal.

FIG. 7B depicts a perspective top view of an embodiment of theimplantable subcutaneous port of the present invention during one stageof removal.

FIG. 7C depicts a perspective view of an embodiment of the implantablesubcutaneous port of the present invention during one stage of removal.

FIG. 8 depicts a top perspective view of a portion of one embodiment ofthe implantable subcutaneous port of the present invention.

FIG. 9A depicts a cross-sectioned end view of one embodiment of theimplantable subcutaneous port of the present invention.

FIG. 9B depicts an end view of one embodiment of the implantablesubcutaneous port of the present invention.

FIG. 10 depicts a schematic of one embodiment of a method of removing animplanted subcutaneous port.

DETAILED DESCRIPTION

The present invention provides a medical device that is capable ofimplantation within a patient for long-term treatments. The device ofthe present invention includes a base, or port, that functions as animplanted medical port capable of receiving, routing, and anchoring atreatment component, such as for example a fluid conduit, power cable orfiber optic cable, that extends through the patient's skin into thepatient's internal physiology. The port is deformable for facilitatingremoval. The port also is shaped to maximize comfort and ease ofinstallation, and is relatively flat or dome shaped and has anoval-shaped or rounded geometry when viewed from the top. The portfurther may comprise at least one tissue ingrowth surface that helpsfurther anchor the device and establish a biological seal between livingtissue and the port.

Taking FIGS. 1 through 3 together, one embodiment of the implantablesubcutaneous port 100 of the present invention comprises a body portion110 for anchoring a transcutaneous treatment component 200. In allembodiments, the body portion 110 may be dome shaped or flat. The bodyportion 110 receives the transcutaneous treatment component 200 beneaththe point of entry 115, such as an incision in a dermal layer 300, androutes the transcutaneous treatment component into the physiology of thepatient. The body portion 110 preferably is produced from a deformablepolymer material for example, such as but not limited to, polyurethane,silicone, or any soft material having a durometer between 40 on theShore A scale and 70 on the Shore D scale. The body portion 110 has anarea footprint 112, and defines a support wall 120 through which thetreatment component 200 enters the body portion 110. Like a conduit, thesupport wall defines an orifice through which the transcutaneouscomponent passes. In one embodiment, the support wall is annular anddefines a generally round orifice for accommodating a generallycylindrically shaped transcutaneous treatment component, but otherembodiments may comprise an support wall defining a rectangle, hexagon,slit or any other geometric configuration suitable for the passage of aparticularly shaped treatment component. The embodiment of theimplantable subcutaneous port 100 of FIG. 1 comprises an annular supportwall 120 defining a substantially round opening into the body portion110. The support wall 120 is disposed at the top of the body portion 110for positioning beneath the opening through the dermal layer 300 thatdefines the point of entry 115 of the transcutaneous treatment component200.

The implantable subcutaneous port 100 comprises one or more frangiblelines 125 formed within the body portion, the fracture of which enablesremoval of the body portion 110 from the inner physiology of a patientthrough a transcutaneous opening defining an area of less than thirtypercent of the area footprint 112 of the body portion 110. Furthermore,in some embodiments, the longest dimension of the transcutaneous openingis no more than 50 percent of the longest dimension of the major planeof the body portion. In one embodiment, the transcutaneous opening isthe point of entry 115 of the transcutaneous treatment component 200. Inanother embodiment, the transcutaneous opening is an incision 400adjacent the body portion 110, as indicated in FIG. 4. Preferablythough, the length of the incision 400 is no more than 50 percent thanthe longest dimension of the body portion 110. For example, theembodiment of the body portion 110 of FIGS. 1A through 4 is generallyround and has a longest dimension along its diameter. The length of anincision therefore would be no greater than half of the diameter of thebody portion 110. Limiting the size of the incision 400 reduces theamount of trauma inflicted on the patient, thereby reducing the risk ofinfection.

The implantable subcutaneous port 100 may further comprise a tissueingrowth skirt 130 made at least partially from a tissue ingrowthmaterial and disposed the body portion about the support wall 120. Thisplacement promotes tissue ingrowth into the tissue ingrowth skirt 130around the point of entry 115 of the transcutaneous treatment component200 so that a biological seal helps protect against infectiouspathogens. In one embodiment the tissue ingrowth skirt may 130 bepartially or completely bioabsorbable so that any portion remainingbehind will safely degrade. In all embodiments having a tissue ingrowthskirt 130, following a period of tissue ingrowth, the force required toseparate the body portion 110 from the tissue ingrowth skirt 130 is lessthan the force required to remove the tissue ingrowth skirt 130 from thedermal layer 300. This enables removal of the body portion 110 whileleaving behind part or all of the tissue ingrowth skirt 130, asindicated in the embodiment depicted in FIG. 8.

Returning now to the configuration of the one or more frangible lines125, placement of the one or more frangible lines 125 along the bodyportion 100 enables a clinician to fracture the body portion 110 intoone or more lengths or sections for removal through a transcutaneousopening that is relatively smaller than the dermal incision required forplacing the entire subcutaneous implantable port 100 at the outset ofpatient treatment. In certain embodiments, the body portion 110 isremovable through the point of entry 115 of the transcutaneous treatmentcomponent 200 following removal of that element. Because of theelimination of any additional incision, such embodiments prevent apatient from enduring further trauma, and further reduce risk ofinfection and other risks associated with surgical procedures.

In one embodiment, the one or more frangible lines 125 may form one ormore paths extending between the support wall 120 and the outerperimeter 132 of the body portion 110 so that the body portion 110 issectioned by the one or more frangible lines 125 into one or moreremovable pieces. The one or more paths of the one or more frangiblelines 125 may be intersecting and/or non-intersecting so as to dividethe body portion 110 into pieces sized for removal through a relativelysmall transcutaneous opening. In one embodiment, the one or morefrangible lines form a continuous path extending between the supportwall 120 and an outer perimeter 132 of the body portion 110. Forexample, in one embodiment shown in FIG. 1, the one or more frangiblelines 125 may form one or more spirals wound around the orifice definedby the support wall 120 and spanning between the support wall 120 andthe outer perimeter 132. This embodiment enables a clinician to fracturethe body portion 110 along the one or more frangible lines 125 anduncoil the body portion 110 for removal in long, thin strips, asdepicted fore example in FIGS. 7A through 7C. In yet another embodiment(not shown), the one or more frangible lines 125 form one or more pathsacross the major plane of the body portion 110, extending between twopoints on the outer perimeter and thereby sectioning the body portion110 into two or more adjacent strips.

In still yet another embodiment (not shown), the body portion 110 isdome shaped and the one or more frangible lines 125 form one or moreclosed circuitous paths in the major plane of the body portion 110,thereby sectioning the body portion 110 into two or more stackedsections. In a similar embodiment (not shown) the body portion 110 issubstantially flat and the one or more frangible lines 125 form one ormore closed circuitous paths in the major plane of the body portion 110,thereby sectioning the body portion 110 into two or more nestedsections. Because the body portion 110 is made from a deformablematerial, the two or more stacked or nested sections are at leastpartially collapsible for facilitating removal through a transcutaneousopening having an area no larger than 30 percent of the area footprint112. In embodiments where the body portion 110 is removed through thepoint of entry 115 of the transcutaneous treatment component 200, thearea of that transcutaneous opening may be a little as 10 to 15 percentof the area footprint 112 of the body portion 110.

As indicated in FIG. 1, in certain embodiments, the one or morefrangible lines 125 each have a pulling end 135 and a terminal end 140.The pulling end 135 enables a clinician to initiate a tear along the oneor more frangible lines 125 at a particular graspable point on the bodyportion 110. The embodiment of FIG. 1 also comprises a stiffener 142disposed on the body portion 110 between the pulling end 135 and theterminal end 140. The stiffener 142 may be a localized thickening of thebody portion 110 or an appended element disposed on and integrated withthe body portion 110 for assisting with directing tear propagation alongthe one or more frangible lines 125. In effect, the stiffener 142prevents shearing or tearing along an area of the body portion 110located between two relatively closely-spaced portions of the one ormore frangible lines 125. For example, in the embodiment of FIG. 1,tearing begins at the pulling end 135 along the one or more frangiblelines 125 in the direction of location A. The tear propagates tolocation B and location C, wraps around the body portion 110 and turns asharp corner between D and E. At point E, the tear could propagate ineither of two directions if not for the presence of the stiffener 142.The stiffener 142 prevents tearing in an undesired direction and forcespropagation of the tear in the direction of pointes F, G and eventuallyH, located at the terminal end 140. In the embodiment of FIG. 1, thestiffener 142 therefore assists with fully unraveling the body portion110 for easy removal in one long, narrow strip.

In some embodiments, the implantable subcutaneous port 100 furthercomprises a gripping element 145 disposed on body portion 110 adjacentthe pulling end 135, as depicted in FIGS. 5A through 7C. In theembodiment of FIGS. 5A through 7C, the gripping element 145 extendswithin the area footprint 112 of the body portion 110, starting at anouter perimeter 132 of the body portion and extending up to an insertedtranscutaneous treatment component 200. In the embodiment of FIGS. 5Athrough 7C, the gripping element 145 extends from the outer perimeter132 of the body portion 110, but, alternatively, the gripping element145 may extend from any point on the body portion 110. For example, thegripping element 145 may be disposed on the body portion 110 at a pointlocated directly beneath the support wall 120 for increasedaccessibility as compared to the embodiment placing the gripping element145 closer to the outer perimeter 132 and therefore deeper within thephysiology of the patient. In still yet another embodiment, the grippingelement may extend beyond the area footprint 112 of the body portion110.

In some embodiments, the gripping element 145 may terminate in acontoured end 147 for accommodating the contours of the adjacenttranscutaneous treatment component 200 and/or for assisting withdirecting the treatment component into the physiology of a patient. Inthe embodiment of FIGS. 5A through 7C, the gripping element 145terminates at a contoured end 147 reachable through the orifice definedby the support wall 120. As FIG. 5B clearly depicts, the contoured end147 directs an inserted treatment component through the body portion 110at a proscribed angle. Following removal of the treatment component, aclinician may insert a retrieval implement 500, such as forceps ortweezers, through the support wall 120 for grasping the gripping element145 and pulling that gripping element 145 up through the support wall120 and out of the a patient with the unraveling body portion 110 intow. Gripping the gripping element 145 from a point external to thephysiology of a patient and applying a force outward from the majorplane of the body portion 110 therefore results in fracturing the one ormore frangible lines 125 and unraveling the body portion 110 along thoseone or more frangible lines 125. Applying a slight torque or twistingmotion during the application of outward force may assist in fracturingthe one or more frangible lines 125. In some embodiments, a notch 150disposed near the pulling end 135 and adjacent the intersection of thepulling end 135 and the gripping element 145 may assist with the initialpropagation of a tear along the frangible line 125. FIGS. 9A and 9Bdepict such an embodiment.

Alternatively, in certain embodiments (not shown), the body portion 110may comprise one or more puncture points, or relatively thin wallsections, that enable a clinician to puncture the body portion 110 withan implement at a point near the one or more frangible lines 125. Theclinician then may grasp the wall of the body portion 110 with theretrieval implement 500, and pull on the body portion 110 to initiatinga tear along the one or more frangible lines 125. This puncturetechnique may be particularly useful in embodiments such as thosedescribed above having one or more frangible lines 125 forming closedcircuitous paths in the body potion 110 and thereby separating the bodyportion 110 into two or more stacked sections. Those embodiments,however, may benefit from the inclusion of one or more gripping elements145 as well. In all embodiments, the gripping element 145 may bedisposed on the body portion 110 so that tears propagate along the oneor more frangible lines 145 in more than one direction, starting fromthe point of intersection of the gripping element 145 (or puncturepoint) and the one or more frangible lines 145. Additionally, someembodiments of the body portion 110 may further comprise radiopaque orultrasonically detectable markers disposed at various points along thebody portion 110 to enable a clinician to determine whether or not theentire body portion 110 has been successfully removed.

As described above, the body portion 110 is made of a material having adurometer that enables fracturing along the one or more frangible lines125 under an application of force and that enables a sufficient amountof deformation for removal of the body portion 110 in one or moresections delineated by the one or more frangible lines 125. Spacingbetween the one or more frangible lines 125 is adjustable in accordancewith material selection and, in particular, material elasticity. Aproper combination of material selection and spacing between the one ormore frangible lines 125 prevents shearing or yielding of the unravelingsection of the body portion 110 under an application of force requiredfor removal through a relatively small transcutaneous opening, such asthe point of entry 115 of the transcutaneous treatment component intothe physiology of a patient.

One skilled in the art could form the one or more frangible lines 125within the body portion 110 using numerous manufacturing techniques. Forexample, the body portion 110 may be injection molded with the one ormore frangible lines 125 cast therein, or the one or more frangiblelines 125 may be etched into the formed body portion 110. In certainembodiments, the one or more frangible lines 125 oppose one another andare formed on both the top surface and the underside surface of the bodyportion 110, such that a reduction in thickness occurs from both sides.This type of manufacture is indicated, for example, in the cross sectionview of the embodiment of the implantable subcutaneous port 100 depictedn FIG. 9A. In addition to applying injection molding and etchingtechniques, selective weakening of the body portion 110 along the one ormore frangible lines 125 also could be accomplished by other meansincluding, but not limited to, serial perforation, chemical etching,mechanical skiving, mechanical scoring, or other methods known to thoseskilled in the art. The one or more frangible lines 125 could be formedusing a localized heat treatment that changes the crystalline structureof the material along the one or more frangible lines 125, therebyreducing required shear forces required to tear the body portion 110 atthose specific locations.

One skilled in the art also could apply heat treatments to reflow thematerial of the body portion 110 to form a berm on either side of theone or more frangible lines 125, thereby creating a larger gradientbetween the force required to shear the body portion 110 generally andthe force required to shear the body portion 110 along the one or morefrangible lines 125. In another embodiment, one skilled in the art couldinjection mold such a berm into the body portion 110 along at leastselect sections of the one or more frangible lines 125, therebyproviding further directional control over tear propagation. In someembodiments, localized thickening of the body portion 110 on eitherside, both sides, or alternating sides of the one or more frangiblelines 125 provides further directional control over tear propagationalong the one or more frangible lines 125. In yet another embodiment,the body portion 110 further comprises materials that are highlydegradable and/or bioabsorbable in localized areas. In this embodiment,the body portion 110 has a substantially uniform wall thickness duringinitial placement within the physiology of a patient, but, over time,the degradable or absorbable material weakens the body portion 110 inlocalized areas, thereby creating one or more frangible lines 125.

Turing now to FIG. 10, the present invention also comprises a method ofremoving 1000 an implantable subcutaneous port 100 for anchoring atranscutaneous treatment component 200. In a first step S1010, themethod of removing 1000 comprises removing the treatment component 200from the implantable subcutaneous port 100 and from a transcutaneousopening adjacent the port. The implantable subcutaneous port 100comprises a body portion 110 for receiving the transcutaneous treatmentcomponent 200 beneath the point of entry 115 into the physiology of apatient. The body portion 110 is formed from a deformable material andhas an area footprint 112 defined by the outer perimeter 132 of theimplantable subcutaneous port 100. The body portion 110 comprises asupport wall 120 defining an orifice through which the transcutaneoustreatment component 200 enters into the body portion 110, which furtherroutes the treatment component 200 into the physiology of the patient.Additionally, the implantable subcutaneous port 100 comprises one ormore frangible lines 125 formed within the body portion 110, thefracture of which enables the removal of the body portion 110 from thephysiology of a patient through a transcutaneous opening, such as thepoint of entry 115 of the transcutaneous treatment component 200. Aclinician may remove the body portion 110 through an alternatetranscutaneous opening, such as an incision 400 in the dermal layer 300adjacent the body portion 110. In any embodiment, the transcutaneousopening typically spans an area of less than thirty percent of the areafootprint 112 of the body portion 110.

Turning back to the method of removing 1000 the implantable subcutaneousport 100, a second step S1015 comprises inserting a retrieval implement500 through the transcutaneous opening, and a third step S1020 comprisesgrasping the body portion 110 with the retrieval implement 500 near theone or more frangible lines 125. As depicted in FIG. 6, the body portion110 may further comprise a gripping element 145 disposed adjacent to theone or more frangible lines, wherein gripping the gripping element 145from a point external to the physiology of a patient and applying forceoutward from the major plane of the body portion 110 results infracturing the one or more frangible lines 125. The method of removing1000 may further comprise an incising step S1005 prior to and/orfollowing the first step S1010 of removing the treatment component. Theoptional incising step S1005 comprises a clinician forming an incisionadjacent the body portion 110 for removal of the unraveled or dissectedbody portion 110 and/or the treatment component 200.

Fracturing of the one or more frangible lines 125 resizes the bodyportion into one or more sections sized for removal through thetranscutaneous opening, which has a longest dimension no greater thanfifty percent of the longest dimension of the area footprint 112. Theone or more frangible lines 125 may be configured in any number ofpatterns as described above with regard to embodiments of theimplantable subcutaneous port 100. In an alternate embodiment, alsodescribed above, the body portion 110 comprises no gripping element 145,but instead comprises one or more areas of weakness defined by thinnedwall sections disposed adjacent the one or more frangible lines 125. Aclinician may puncture the body portion 110 in these one or more areasof weakness with a retrieval implement 500 and then grasp the wall ofthe body portion 110 while applying an outward force to propagate a tearalong the one or more frangible lines 125 and in one or more directionsfrom the point of puncture initiation.

Returning to the method of removing 1000, a fourth step S1025 comprisesapplying a force outward from the body portion 110 and away from thepatient so that the one or more frangible lines 125 fracture, therebysectioning the body portion 110 into one or more pieces. As furtherindicated in the embodiment of FIGS. 7A through 7C, pulling the grippingelement 145 further away from the body portion 110 further unravels andremoves the portion of the body portion 110 attached to the grippingelement 145. The method of removing 1000 comprises a final step S1030 ofpulling the one or more pieces of the body portion 110 through thetranscutaneous opening, here the point of entry 115, and out of thephysiology of the patient. In certain embodiments, the method ofremoving 1000 further comprises separating the body portion 110 from allor part of a tissue ingrowth skirt 130 disposed thereon for promotingtissue ingrowth around the point of entry 115 of the transcutaneoustreatment component 200. For example, in the embodiment depicted inFIGS. 7A through 8, the body portion 110 unravels, leaving behind theentire tissue ingrowth skirt 130 under the dermal layer 300. Preferably,this tissue ingrowth skirt 130 is also biodegradable and/orbioabsorbable so that the physiology of the patient dissolves and clearsthe tissue ingrowth skirt 130 over time. In alternate embodiments thetissue ingrowth skirt 130 can be made of a material that is suitable foruse as a permanent implant, such a polyester velour fabric, which isused on a wide range of permanently implanted medical devices.

It is noted that the foregoing examples have been provided merely forthe purpose of explanation and are in no way to be construed as limitingof the present invention. While the present invention has been describedwith reference to an exemplary embodiment, it is understood that thewords, which have been used herein, are words of description andillustration, rather than words of limitation. Changes may be made,within the purview of the appended claims, as presently stated and asamended, without departing from the scope and spirit of the presentinvention in its aspects. Although the present invention has beendescribed herein with reference to particular means, materials andembodiments, the present invention is not intended to be limited to theparticulars disclosed herein; rather, the present invention extends toall functionally equivalent structures, methods and uses, such as arewithin the scope of the appended claims.

1) An implantable subcutaneous port for anchoring a transcutaneoustreatment component, comprising: a) a body portion for receiving thetranscutaneous treatment component beneath the point of entry into thephysiology of a patient and routing the transcutaneous treatmentcomponent, the body portion being produced from a deformable materialand having an area footprint and defining an support wall through whichthe transcutaneous treatment component enters the body portion; and b)one or more frangible lines formed within the body portion, the fractureof which enables the removal of the body portion from the physiology ofthe patient through a transcutaneous opening defining an area of lessthan thirty percent of the area footprint of the body portion. 2) Theimplantable subcutaneous port of claim wherein the support wall isannular. 3) The implantable subcutaneous port of claim 1 furthercomprising a tissue ingrowth skirt disposed on the body portion aboutthe support wall for promoting ingrowth at least about the point ofentry of the transcutaneous treatment component. 4) The implantablesubcutaneous port of claim 1 wherein the transcutaneous opening is thepoint of entry of the transcutaneous treatment component. 5) Theimplantable subcutaneous port of claim 1 wherein the transcutaneousopening is an incision adjacent to the body portion. 6) The implantablesubcutaneous port of claim 1 wherein the longest dimension of thetranscutaneous opening is no more than 50 percent of the longestdimension of the major plane of the body portion. 7) The implantablesubcutaneous port of claim 1 wherein the one or more frangible linesform a continuous path extending between the support wall and an outerperimeter of the body portion. 8) The implantable subcutaneous port ofclaim 7 wherein the continuous path forms a spiral. 9) The implantablesubcutaneous port of claim 1 wherein the one or more frangible linesform one or more paths extending between the support wall and the outerperimeter of the body portion so that the body portion is sectioned bythe one or more frangible lines into one or more removable pieces. 10)The implantable subcutaneous port of claim 1 wherein the body portion isdome shaped. 11) The implantable subcutaneous port of claim 10 whereinthe one or more frangible lines form one or more closed circuitous pathsin the major plane of the body portion thereby sectioning the bodyportion into two or more stacked sections. 12) The implantablesubcutaneous port of claim 11 further comprising a gripping elementdisposed on one or more of the two or more stacked sections andextending within the area footprint of the body portion, whereingripping the gripping element from a point external to the physiology ofa patient and applying force outward from the major plane of the bodyportion results in fracturing the one or more frangible lines. 13) Theimplantable subcutaneous port of claim 1 wherein the body portion issubstantially flat. 14) The implantable subcutaneous port of claim 13wherein the one or more frangible lines form one or more closedcircuitous paths in the major plane of the body portion therebysectioning the body portion into two or more nested sections. 15) Theimplantable subcutaneous port of claim 11 further comprising a grippingelement disposed on one or more of the two or more nested sections andextending within the area footprint of the body portion, whereingripping the gripping element from a point external to the physiology ofa patient and applying force outward from the major plane of the bodyportion results in fracturing the one or more frangible lines. 16) Theimplantable subcutaneous port of claim 1 wherein the one or morefrangible lines form one or more paths across the major plane of thebody portion 110, extending between two points on the outer perimeterand thereby sectioning the body portion 110 into two or more adjacentsections. 17) The implantable subcutaneous port of claim 16 wherein theone or more paths are non-intersecting. 18) The implantable subcutaneousport of claim 16 wherein the one or more paths intersect. 19) Theimplantable subcutaneous port of claim 1 wherein each of the one or morefrangible lines has a pulling end and a terminal end. 20) Theimplantable subcutaneous port of claim 19 further comprising a grippingelement disposed on the body portion adjacent the pulling end andextending within the area footprint of the body portion, whereingripping the gripping element from a point external to the physiology ofa patient and applying force outward from the major plane of the bodyportion results in fracturing the one or more frangible lines. 21) Theimplantable subcutaneous port of claim 19 further comprising a puncturepoint adjacent the pulling end for puncturing the body portion toinitiate a tear along the one or more frangible lines. 22) Theimplantable subcutaneous port of claim 21 wherein the puncture point isa relatively thin section of the body portion. 23) The implantablesubcutaneous port of claim 19 further comprising a notch adjacent thepulling end of each of the one or more frangible lines for assisting inpropagating a fracture along each of the one or more frangible lines.24) A method for removing a subcutaneous port for anchoring atranscutaneous treatment component, comprising: a) removing thetreatment component from the port and from a transcutaneous openingadjacent the port, wherein the port comprises i) a body portion forreceiving the transcutaneous treatment component beneath the point ofentry into the physiology of a patient and routing the transcutaneoustreatment component, the body portion being produced from a deformablematerial and having an area footprint and defining a support wallthrough which the transcutaneous treatment component enters the bodyportion; and ii) one or more frangible lines formed within the bodyportion, the fracture of which enables the removal of the body portionfrom the physiology of the patient through a transcutaneous openingdefining an area of less than thirty percent of the area footprint ofthe body portion; b) inserting a retrieval implement through thetranscutaneous opening; c) grasping the body portion with the retrievalimplement near the one or more frangible lines; d) applying a forceoutward from the body portion so that the one or more frangible linesfracture, thereby sectioning the body portion into one or more pieces;and e) pulling the one or more pieces of the body portion through thetranscutaneous opening. 25) The method of claim 24 wherein the supportwall is annular. 26) The method of claim 24, further comprising a stepbefore step a) of creating a transcutaneous opening. 27) The method ofclaim 24 wherein the port further comprise a tissue ingrowth skirtdisposed on the body portion about the support wall for promotingingrowth at least about the point of entry of the transcutaneoustreatment component. 28) The method of claim 27 further comprising astep between d) and e) of pulling the one or more pieces apart from thetissue ingrowth skirt, thereby leaving the tissue ingrowth skirt withinthe physiology of the patient. 29) The method of claim 24 wherein thetranscutaneous opening is the point of entry of the transcutaneoustreatment component. 30) The method of claim 24 wherein thetranscutaneous opening is an incision adjacent to the body portion. 31)The implantable subcutaneous port of claim 24 wherein the longestdimension of the transcutaneous opening is no more than 50 percent ofthe longest dimension of the major plane of the body portion. 32) Themethod of claim 24 wherein the one or more frangible lines extend in acontinuous path between the support wall and an outer perimeter of thebody portion. 33) The method of claim 32 wherein the continuous pathwinds about the body portion in a spiral. 34) The method of claim 24wherein the one or more frangible lines form one or more paths extendingbetween the support wall and the outer perimeter of the body portion sothat the body portion is sectioned by the one or more frangible linesinto one or more removable pieces. 35) The implantable subcutaneous portof claim 34 wherein the one or more paths are non-intersecting. 36) Theimplantable subcutaneous port of claim 34 wherein the one or more pathsintersect. 37) The method of claim 24 wherein the body portion is domeshaped. 38) The method of claim 37 wherein the one or more frangiblelines form one or more closed circuitous paths in the major plane of thebody portion thereby sectioning the body portion into two or morestacked sections. 39) The method of claim 39 further comprising agripping element disposed on one or more of the two or more stackedsections and extending within the area footprint of the body portion,wherein gripping the gripping element from a point external to thephysiology of a patient and applying force outward from the major planeof the body portion results in fracturing the one or more frangiblelines. 40) The method of claim 24 wherein the body portion issubstantially flat. 41) The method of claim 40 wherein the one or morefrangible lines form one or more closed circuitous paths in the majorplane of the body portion thereby sectioning the body portion into twoor more nested sections. 42) The method of claim 41 further comprising agripping element disposed on one or more of the two or more nestedsections and extending within the area footprint of the body portion,wherein gripping the gripping element from a point external to thephysiology of a patient and applying force outward from the major planeof the body portion results in fracturing the one or more frangiblelines. 43) The method of claim 24 wherein each of the one or morefrangible lines has a pulling end and a terminal end. 44) The method ofclaim 43 further comprising a gripping element disposed on the bodyportion adjacent to the pulling end and extending within the areafootprint of the body portion, wherein gripping the gripping elementfrom a point external to the physiology of a patient and applying forceoutward from the major plane of the body portion results in fracturingthe one or more frangible lines. 45) The method of claim 43 furthercomprising a puncture point adjacent the pulling end for puncturing thebody portion to initiate a tear along the one or more frangible lines.46) The method of claim 45 wherein the puncture point is a relativelythin section of the body portion. 47) The method of claim 43 furthercomprising a notch adjacent the pulling end of each of the one or morefrangible lines for assisting in propagating a fracture along each ofthe one or more frangible lines. 48) An implantable subcutaneous portfor anchoring a transcutaneous treatment component, comprising: a) abody portion for receiving the transcutaneous treatment componentbeneath the point of entry into the physiology of a patient and routingthe transcutaneous treatment component, the body portion being producedfrom a deformable material and having an area footprint and defining anannular support wall; b) at least one frangible line extending along acontinuous path between an outer perimeter of the body portion and theannular support wall; and c) at least one gripping element disposed onthe body portion at a point adjacent to the least one frangible line, i)wherein gripping the at least one gripping element from a point externalto the body of a patient and applying force outward from the major planeof the body portion results in fracturing the at least one frangibleline along the continuous path between outer perimeter of the bodyportion and the annular support wall, thereby enabling removal of theimplanted catheter routing port from the body of the patient through atranscutaneous opening defining an area of less than thirty percent ofthe area footprint of the body portion.